Drinks That Worsen And Improve Blood Glucose Levels

Mirthe Precision Health
4 min readAug 18, 2023


Blood sugar control is crucial to optimal health and anti-ageing. Excess spikes and drops in ones blood sugar are linked to an extensive range of ill health effects, from a less capable immune system (think infections, autoimmune conditions and even cancers, via a process called ‘immune escape’) to the formation of ‘AGES’ (advanced glycation end products) that literally ‘age’ us from the inside out. Head over to my podcast episode for more details on the effects of sugar on health.

Today’s post is about drinks, and which often consumed ‘healthy options’ may secretly create havoc on your body.

Drinks that worsen blood glucose levels:

  • Let’s start with the obvious ones — soft drinks. Most of you likely are aware that soft drinks like coca cola, lemonade, but also tonic water (hello, Gin & Tonic) pack a bunch of sugar, without any nutrients, making them some of the worst offenders, and entirely ‘empty’ calories and sugar spikes.
  • However, and what many aren’t quite aware of, fruit juices can be just as bad as it pertains to their effect on blood sugar! Often touted as a healthy choice (who didn’t grow up thinking a glass of orange juice would be a superfood?), you may think twice before reaching to that fruit juice. Ouch!
  • And what about coke zero and the like? While consuming ‘zero-sugar’ alternatives may not have an impact on ones blood sugar, research suggests that they are linked to blood sugar control issues in the long run. Artificial sugar alternatives like aspartame and sucralose have been shown to mess with our cells’ ability to respond to insulin properly, contributing to blood sugar swings and, if continued for a very long time, potentially even a higher risk of the likes of type 2 diabetes and metabolic syndrome. While more research needs to be done, a likely reason appears to be that these fake sugar alternatives mess with our gut microbiome (that intricate balance of different bacteria in our gut) — which is linked to how well our body responds to sugars! I did a deep dive into the effects on health of aspartame and other sugars recently, head over to my blog post on that topic if you’d like to find out more, or listen to my podcast about it here.

While juices are out, smoothies can be a better option, depending on their content. The fiber that is generally still present in smoothies slows the absorption of sugars in the gut, supporting not only a healthier gut microbiome by feeding the good bugs in there (prebiotics!), but also balancing blood sugar levels. However, be aware that if that smoothie consists of fruit, it may still spike your blood sugar! Low sugar versions such as berries and greens, plus protein, can be a better choice. Better yet (and what I generally recommend to my clients and patients, unless they have issues with SIBO and bloating after eating high fiber meals, where it can temporarily be needed to lower fiber content until the gut is healed), eat the real food rather than to drink it, as the process of chewing and breaking down the foods allows for our digestive tract to do its wonderful miracles and keeps blood sugar more balanced.

Some surprising drinks that may help with blood sugar control (if consumed in moderation):

Despite alcohol in excess being detrimental to our health, small amounts of low sugar drinks, in particular dry red wine, but also likely tequila, vodka or gin with sparkling water or on the rocks (no, not with tonic water, which is basically pure sugar water!) have been shown to improve blood sugar levels!

Same goes for coffee- if consumed in moderation, coffee has an insulin sensitising effect on our cells, keeping blood sugar nice and steady. However, if consuming in excess, coffee will spike our stress biochemistry, leading to blood sugar spikes.

Adding some good fats and protein such as found in full fat milk (or sugar free milk alternatives) may help dampen any spikes.

Which brings us to the next topic — oat milk! While being touted as a wonderful superfood, and consuming whole oats in their unprocessed version in small amounts does show some great benefits to cholesterol levels and pack in a bunch of nutrients, consuming the refined variety in form of oat milk will most likely contribute to your blood sugar being out of control.

It is always important to realise that everyone’s body responds slightly differently, and you may want to consider trialing a continuous blood glucose monitor once. These devices can be bought online for roughly £50, are worn for 2 weeks, and you can continuously measure what your blood sugar is doing — so that you if having that second latte is tipping you over the edge, what type of milk seems to resonate best with your blood sugar control, etc. Welcome, era of personalised medicine and home tracking tools!

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Mirthe Precision Health

Functional Medicine Practitioner. Hormones, epigenetics, health optimisation. IG/ TikTok/ Youtube/ Fb: @mirthe_precisionhealth, www.functionalmedicine.me.uk,